In CAO, the server object's lifetime is controlled by
clients, which is the reason we do not normally prefer this activation method
in remoting applications. Not preferring CAO is good when the server does most
of the critical business logic and execution. But when the client performs
critical tasks where data loss may affect the system, then we may need to
choose CAO instead of SAO.
When we register ActivatedClientType at the client then we
create the remote object using new operator- server initialize instance
of remote object. So it means the server executes default constructor.
The server executes the constructor for each
client only once unless and until the client gets restarted or
creates new instance of remote object again for subsequent remote method call.
Since the server creates the remote object instance for each
client separately, class variables can be common for specific clients only. It
means we can have state management for client by client separately, which will
not be common to all clients. It also means that we can manage state of
particular among all method calls of the same client at the server. Therefore,
in CAO remoting implementation we can not have single server object intendance
to serve all clients.
In CAO remoting implementation server object never gets
garbage collected even if it remains idle for long or all clients stop invoking
remote methods. The lifetime of server object instance is controlled by the
respective clients. CAO is also called statefull objects.
A Client can use either of the following ways to create CAO
object at the server
Using New operator to create object
instance
Limitation in this approach - Unlike SAO’s, you can not use
shared interface or base classes. It means that you will need to provide your
compiled server class to the client application. Sharing the actual server
implementation to the client is not a feasible way. One better option would be
to use soapsuds on server object to get the metadata which could be used by the
client.
Using Activator.CreateInstance method
You can use it to create remote object instance by passing
constructor parameters.
